(a) Field of the Invention
The present invention relates to a fluorescent tube structure, which fluoresces when connecting electric power, and more particularly to apply layers of pellicles to an inner surface of the fluorescent tube and a base plate to enhance illuminant efficiency. The present invention can be used as a backlight of illuminating and electronic display devices.
(b) Description of the Prior Art
Referring to FIG. 1. A conventional fluorescent tube 10, short in life and fast in illumination decay, is formed by applying diluted fluorescent material 12 to an inner surface of a glass tube 11 and then assembled after processing. Referring to FIG. 2. Another conventional fluorescent tube 10, usually with a thickness over 10 mm, is formed by infusing into mercury, Ar, Ne, and Kr etc after vacuuming. Due to a thicker thickness, the tube 10 requires a larger room to install, which lowers the efficiency. With the tube 10 usually used as an illuminating device installing on the ceiling and with its thick and long tube, heat generating from illuminating rises the tube temperature, which yellows the tube after long use, causing a downgrade in illuminant efficiency and also a possible fire.
Another type of illuminant is a backlight of an electronic display device, which divided into an edge side illuminant and a rear direct illuminant. The edge side illuminant, low in luminance and high in cost, is to place an illuminant (Light Emitting Diode, LED) on a lateral of a light guide plate to guide light through the light guide plate to a reflective sheet, wherein forming an area illuminant, and further to illuminate a LCD panel. The rear direct illuminant uses a Cold Cathode Fluorescence Lamp (CCFL) as the illuminant placed on the rear of the LCD, wherein an expand sheet formed in front and a reflective sheet behind. Light from the CCFL will be reflected and expanded and finally illuminated the LCD panel. The rear direct illuminant requires a wider fluorescent tubes' spacing and a thicker tube thickness, which may generate shadows and requires a large installation space, respectively.